Sheathing apparatus

ABSTRACT

Baled material (4) is fed into a resilient sheath (4) through an open end thereof with at least the open end portion held in a resiliently expanded condition so that after insertion of the material the sheath can contract around the material, so expelling excess air. The sheath is held by a holding device having members (25; 124) movable on cranks between positions in which the sheath can be readily located on the members in its unstressed condition and in which at least the open end of the sheath is enlarged by stretching.

This is a continuation of copending application(s) Ser. No. 07/730,776filed on Nov. 29, 1991 abandoned.

The present invention relates to a method of and an apparatus forplacing material, for example, straw, grass, hay or silage, which may,but need not be formed into bales, within a tubular sheath.

There is known from GB 2 136 761 A, a bale-sheathing device comprising amobile sheath-carrying structure arranged to support and hold open anaxially closed-up portion of a tubular sheath in a manner enabling saidclosed-up portion to be progressively pulled out rearwardly off thesheath-carrying structure, and bale lifting and guide means carried bythe mobile sheath-carrying structure and arranged to lift up a bale tobe sheathed and guide it through the closed-up portion of the sheath asthe device is advanced relative to the bale, the device being soarranged that after passage through the closed-up portion of the sheath,the bale is put down again whereby, in use of the device, the bale comesto rest within an axially opened-out part of the sheath pulled out offthe structure during advance of the device.

It was proposed in GB 2 136 761 A that this device be used to sheathbales within tubular plastic sheaths of greater diameter than the bales.Thus, for example, tubular plastics sheaths of 2 m diameter and up to 80m in length were proposed to be used for containing large round bales ofup to 1.8 m in diameter.

It has however now been appreciated that the relatively large volume ofair necessarily contained within a plastics sheath of this dimensionalrelationship with the baled material can promote undesired fermentation.Also, the slack portions of the sheath are liable to be snagged andtorn. The present invention is thus concerned with the provision of asheathing method and apparatus by which these disadvantages may beovercome.

The present invention accordingly provides a method of and an apparatusfor sheathing material in which the material is fed into a resilientsheath through an open end thereof with at least the open end portion ofthe sheath held in a resiliently expanded condition so that afterinsertion of the material the sheath can contract around the material,so expelling excess air.

The sheath can thus be held during insertion of the material by aholding device having a first position in which the sheath can bereadily located on the device in its unstressed condition. The devicecan then be operated so as to enlarge at least the open end of thesheath by stretching of the resilient plastics sheet of which it isconstructed.

The holding device can comprise a plurality of cranks spaced around theperiphery of a support ring, the cranks having mounting portionsjournalled on the ring about axes parallel to the ring axis and axiallyoffset parallel support portions extending away from the ring in thedirection in which the material is to be loaded into the sheath.Initially, the cranks are positioned so that the support portions areall located at their innermost positions. The sheath has a diameter inits relaxed condition which is intermediate between that of the ring andthat of the circle on which the crank second portions initially lie, sothe sheath can be readily placed on the cranks. Rotation of the crankson the support ring effects movement of the support portions outwardlyto positions adjacent the support ring periphery,so this movementstretches the sheath side wall so that the sheath has an open end of across-section approximating to that of the support ring.

The rotation of the mounting portions of the cranks about their axes canbe effected by any suitable common drive mechanism. For example, thecranks may be mechanically linked by a linkage acted upon by anhydraulic ram. Alternatively, the mounting portions could be rotated byrotation of an outer ring to which the cranks are in driven relationshipby means of gear teeth on the outer ring and meshing with gear teeth onthe mounting portions.

In the stretched condition of the sheath, the material to be sheathed,preferably but not necessarily in the form of bales, can enter thestretched sheath through the support ring by appropriate relativemovement of material and the apparatus. The support ring can thus becarried by a frame which can be connected to a powered vehicle, forexample, a tractor, so as to be driven over a field so as to move intothe sheath baled material awaiting sheathing.

Any convenient equipment can be used to effect filling of the sheathwith the material to be enclosed, for example, the bale lifting andguiding means disclosed in GB 2 136 761 A where the material isavailable in baled form. Blades or wheels or rollers can thus beprovided to engage underneath the material and also to engage its sidesif in baled form, so as to guide the material into the sheath. Aconveyor for example a passive belt conveyor can be employed instead orin addition to such guide means.

Preferably the sheath is initially contracted lengthwise, as by beingbunched, convoluted or formed with bellows-like folds as taught in GB 2136 761 A. When feeding in of the material begins, by relative movementof the material and the sheath and its holding device, the sheath isthen extended lengthwise off the holding device by the incoming materialso as to contract resiliently around it. The sheath can be a blown filmof plastics material capable of being stretched in respect of itscircumference by about 25%. Because of its plastics memory the sheathwill shrink back to about 5% extension within 30 minutes of release witha further contraction over the next 24 hours.

The present invention thus provides for the enclosure in a plasticssheath of straw, hay or silage material, for example, in a convenientand efficient way, by use of simple apparatus. The material is compactlyensheathed without undue free air space within the sheath, so thatundesired fermentation is restricted or eliminated. The material issheathed in such a way that the sheath is resistant to being split ortorn, and because of the tight fit of the material within the sheath, aminimal quantity of sheathing material is employed.

The invention is further described below, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a front view of a first apparatus in accordance with theinvention;

FIG. 2 is a sectional side view of the apparatus of FIG. 1 in use andwith parts omitted;

FIG. 3 is a plan view of the apparatus of FIGS. 1 and 2 again shown inuse and with parts omitted;

FIGS. 4 & 5 are respectively front and side views of a second apparatusin accordance with the invention; and

FIG. 6 is a fragmentary perspective view of a modification of theapparatus of FIGS. 4 and 5.

The illustrated apparatus 1 is particularly suitable for enclosing largegenerally cylindrical bales of for example 1.22 meters (48 inches) indiameter in a tubular sheath of resiliently stretchable plasticsmaterial having a rather smaller unstretched diameter for example 1.14meters (45 inches) in its relaxed or unstretched condition.

The apparatus 1 comprises a movable sheath support structure mounted ontwo ground engaging skids 3. The support ring structure includes a rigidmetal ring 5 defining an entry mouth 6 large enough to allow the passagetherethrough of the large round bales of about 1.22 meters in diameterwith limited but adequate clearance. The ring 5 mounts around itsperiphery sheath holding or support means, described in detail below,capable of holding at least an open end portion of a tubular plasticssheath 4 of resiliently stretchable material with the open end portionstretched open from a relaxed or unstressed condition, so as tocorrespond at least approximately in cross-section to that of the mouth6. The sheath 4 is held on the holding or support means in a conditionin which it is not only stretched open but in which it is also axiallyclosed up or contracted as by being concertinered or otherwise providedwith peripheral folds so as to considerably shorten its axial length, asindicated in FIG. 2. Initially, the shortened axial length can be littlemore than the length of the support means even with a sheath of some 61m. (200 feet) length.

Each skid 3 is rigidly connected to the ring 5 by means of a respectiveleg 7 and strut 8. The skids 3 are arranged to support the supportstructure at a height off the ground sufficient to ensure that the gapbeneath the bottom of the structure and the ground is large enough toprevent the stretched, bunched-up, sheath on the structure, dragging onthe ground upon advance of the apparatus on the skids. In practice, thegap between the support structure and ground is of the order of 0.18 m(7 inches).

The apparatus 1 includes means arranged to lift a bale B off the groundand to guide it into the mouth 6 of the support structure. Thesecomprise a pair of blades 10 which project downwardly from the ring 5and forwardly in the intended direction of advance A of the apparatus.The shape and disposition of the blades 10 is such that upon advance ofthe apparatus towards a bale B, the blades engage beneath and onrespective sides of the bale B and progressively lift it into the mouth.A roller 11 carried by the ring 5 at the bottom of the mouth facilitatesthe transfer of the bale B from the blades 10 into the interior of thesupport structure.

To enable the apparatus to be towed by a tractor 13 while leaving thefront of the apparatus unobstructed, an offset towing rig 14 isprovided. This rig 14 includes a transverse bar 15 which is rigidlyconnected to the ring 5 and, in use, can be coupled to the tractor in amanner such that the bar 15 remains orientated transversely of thetractor centre line. In an alternative arrangement, the bar 15 mayextend forwardly as well as transversely (for example, at an angle of45°).

Turning now to the sheath holding or support means carried by the ring5, this comprises a suitable number of cranks 20, for example six,distributed uniformly around the periphery of the ring.

Each crank 20 comprises a rod-like mounting portion 21 extendingparallel to the axis of the ring 5 and journalled in a fitting 22secured to the outer edge of the ring. An intermediate portion 24extends in the release or loading position illustrated in FIG. 1generally radially inwardly of the ring 5, on its downstream side(having regard to the direction indicated by the arrow A). From the freeinner end of the intermediate portion 24, a rod-like support portion 25extends parallel to the first or mounting portion for a lengthsufficient to support the plastics sheath.

The intermediate portions 24 of the cranks extend outwardly from themounting portions 21 and are pivotally connected to links 26 whichextend to like pivotal connections with adjacent cranks 20. The links 26thus form a series of links interconnecting all the cranks 20, whichseries may extend entirely around the ring 5.

Movement of the cranks 20 is effected by means shown in FIG. 1 butomitted from FIGS. 2 and 3 for the sake of clarity. One of the cranks20A has an intermediate portion 24 extending outwardly beyond thepivotal connection with the links 26 to a pivotal connection with thepiston rod 27 of an hydraulic ram of which the cylinder 29 is pivotallyconnected to the towing rig 14. By extending and contracting thehydraulic ram, the cranks 20 can be pivoted about the axes of themounting portions 21 on the support ring 5 so as to alter the positionradially of the support portions 25, this movement being conveyed fromthe crank 20A to the other cranks by the links 26, so that all thecranks move uniformly together in the same direction.

Operation of the apparatus is described below. Initially, the hydraulicram 27,29 is moved, if necessary, to its contracted position,corresponding to the radially innermost position of the support portions25 of the cranks 20. The tubular sheath 4, in an axially contractedcondition is then placed on the support portions 25 and the rear end ofthe sheath is closed to form a sealed end 30 at the free ends of thesupport positions. The unstressed diameter of the sheath, typically 1.14meters (45 inches), is such that it can be received on the supportportions 25 in this position without stretching, so that the preferredaxial contraction can be conveniently ensured. As much as 80 m of sheathcan normally be accommodated on the support portions 25.

The hydraulic ram is then extended so as to move the support portions 25outwardly. This outward movement stretches the wall of the sheath 4, soas to increase its peripheral extent. The final outward position of thesupport portions 25, shown in FIG. 2, corresponds at least approximatelyto a stretched condition of the sheath wall in which it forms, ineffect, a continuation of the support ring 5. A sheath having anunstressed diameter of 1.14 meters can be expanded to a diameter ofabout 1.52 meters (60 inches) to accommodate a bale of 1.22 meters.

In order to sheath a row of large round bales B, the apparatus isaligned with one end of the row. The tractor 13 can then be advanced inthe direction of arrow A to move the blades 10 beneath the first bale B,causing the latter to be lifted up through the mouth of the ring 5 andinto the space between the crank support portions and then into theinterior of the stretched and axially contracted sheath.

As the tractor 13 continues its advance, the blades 10 engage beneaththe second bale B and raise this bale up towards the ring mouth, thefirst bale B being pushed by the second along the crank supportportions. With the subsequent passage of the third bale B up the blades10, the first bale B is pushed outwardly beyond the ends of the supportportions. The bale B then engages the sealed end of the sheath 4 andcauses some of the sheath to be drawn off the crank support portions.The portion of the sheath 4 drawn off in this way is pulled out to itsfull axial extent and also resiliently contracts around the bale so asto engage and slightly compress it. It is of course the bunched-upsheath which moves about the bale B rather than vice versa and the firstbale is deposited back on the ground within the sheath when it hasemerged from between the support portions.

This first bale B thereafter serves as an anchor for the sheath 4 sothat as the apparatus moves away from the first bale, a correspondinglength of sheath is pulled off to contract around the second, third andsubsequent bales as these in turn pass through the space between thecrank support portions to be deposited back on the ground, tightlyenclosed by the sheath 4.

All the bales B of the row are thus sheathed in a single continuousoperation. The last bale in a row, or an isolated bale, is moved throughthe apparatus manually or in some other way, as there is no followingbale to "push" this bale right through it.

In FIGS. 4-6 the reference signs used in FIGS. 1-3 are used to indicateparts of the second apparatus 100 of the invention which are identicalor functionally similar to parts of the first apparatus. Except asdescribed below, the second apparatus 100 corresponds in function andconfiguration to the apparatus 1.

The second apparatus 100 again has a support structure including a ring5 supported at one side only by a wheel 103 carried by an arm 107projecting laterally from the lower region of the ring.

To guide the bales B into a sheath stretched onto the sheath holdingmeans of the apparatus 100, a conveyor 110 extends from a positionsomewhat forward of the ring 5 to a rear position approximating to therear end of the sheath holding means. The conveyor has a belt 111 whichmoves on rollers of which the ends are journalled in spaced parallelbearings 112 extending axially from the base of the ring 5. To providelateral support for the bales B, frame members 118 extend forwardly fromthe ring 5 and are bent downwardly and inwardly to terminate Just shortof the forward roller of the conveyor 110.

The apparatus 100 is also arranged to be advanced by a tractor to whichit can be connected by means of the offset towing ring 14. The apparatusis then additionally supported by the wheel 103. When disconnected fromthe tractor, as shown in FIG. 4, the apparatus rests on the wheel, theframe member 115 and the rear ends of the beams 112.

The sheath holding means of the apparatus 100 again comprises cranksoperating similarly to the cranks 20 but comprising arms having inclinedinner and outer portions 121 and 122 pivoted to the ring 5 at the joinof these portions. A rod-like sheath mounting portion 124 extendsaxially rearwardly from the inner end of each inner portion 121 and alink 125 is pivotably connected to the outer end of the outer portion122. The link 125 extends to a pivotal connection to the next outerportion 122 in the direction away from the hydraulic ram, the piston rod27 of which is pivotably connected to the outer end of the adjacentcentre portion 122A. To prevent the sheath end from being stretched in astraight line between the two lowermost portions 124 above the conveyor,a fixed shaft 127 extends parallel to the portions on each side of theconveyor and is received within the sheath together with the portions124.

The sheath holding means of the apparatus 100 can include means forindividual adjustment of the relative positions of the mounting portions124 and/or adjustment of all the portions 124 to accommodate sheaths ofdifferent diameter. Both such adjustments can be provided for by makingthe lengths of the links 25 selectively variable. Conveniently, as shownat the lefthand side of FIG. 4, each link can comprise two tubular endportions 128 having tapped adjacent end portions connected by anintermediate portion 129 threaded so that the portions 128 are drawntogether or spaced apart by rotation of the threaded portion.

In the modification shown in FIG. 6, each of the frame members 115mounts two spaced rollers 130 about rotational axes which are paralleland inclined downwards and inwardly so that the four rollers constitutea roller conveyance of V-shaped cross-section extending rearwardly fromjust forwardly of the conveyor 110 to Just forwardly of the ring 5.

Various modifications to the apparatus described are, of course,possible. For example, the apparatus can be provided with a power drivefor the input rollers or conveyor, or can be made self-propelled ratherthan tractor-drawn. Different forms of the holding device for the sheathcan be employed.

I claim:
 1. A method of storing sheathed bales of agricultural cropmaterial on the ground, said bales each being of large size and heavyweight and having varying cross sectional configurations within adetermined range of cross sectional dimensions, said methodcomprising:providing an elastic tubular bag having an openingtherethrough dimensioned in a relaxed state to be no greater than thesmallest cross section of said bales, and in an elastically expandedstate to be substantially greater than the largest cross section of saidbales; providing a mobile sheathing machine movable along the ground ina defined forward direction, a ring like frame mounted on said machinedefining an opening therethrough with an axis through the openingdirected along the line of movement of said machine, elongated supportrods movably mounted to the frame for radially directed movementinwardly and outwardly from said axis, and a power source for poweredmovement of said support rods between inner and outer positions, saidsupport rods extended rearward of said ring like frame and collectivelydefining an opening at their inner position that is smaller than theopening of said bag in its relaxed state and defining an opening intheir outer position that is larger than the cross sectional dimensionof the largest bale to be stored; and gathering the tubular baglengthwise to fit onto the length of the elongated support rods, movingthe support rods to the inner position, mounting the tubular bag ontothe support rods with the rearward most end of the bag being closed,moving the support rods to their outer position and in the processexpanding the opening through the bag, inserting the bales in sequencethrough the frame, through the defined opening of the support rods andinto the bag opening for deposit thereof onto the ground rearward of themachine, and in the process pulling a portion of the bag off the supportrods which portion contracts around the bale, and in the process movingsaid machine forward to achieve contiguous and stationary depositing ofthe bales onto the ground.
 2. A method as defined in claim 1 whichincludes providing a bale receiving and bale guiding portion on saidmachine and said portion receiving in sequence bales for storage, andguiding said bales for inserting the bales in sequence through theframe.
 3. A method as defined in claim 2 which includes aligning thebales in sequence on the ground and said bale receiving and bale guidingportion configured for receiving and guiding said bales as the machineis moved forward.
 4. A method as defined in claim 3 which includesproviding a tractor and using the tractor for forcibly moving themachine along the aligned bales to sequentially engage, bag, andredeposit the bagged bales on the ground.
 5. A system for storingsheathed bales of agricultural crop material on the ground, said baleseach being of large size and heavy weight and having varying crosssectional configurations within a determined range of cross sectionaldimensions, said bales being sheathed in an elastic tubular bag havingan opening therethrough dimensioned in a relaxed state to be no greaterthan the smallest cross section of said bales, and in an elasticallyexpanded state to be substantially greater than the largest crosssection of said bale, said system comprising:a mobile machine movablealong the ground in a defined forward direction, a ring like framemounted on said machine defining an opening therethrough with an axisthrough the opening directed along the line of movement of said machine,elongated support rods movably mounted to the frame for radiallydirected movement inwardly and outwardly from said axis, and a powersource for powered movement of said support rods between inner and outerpositions, said support rods attached at a front end to the frame andhaving a free rear end extended rearward of said frame, said supportrods collectively defining an opening at their inner position that issmaller than the opening of said bag in its relaxed state and definingan opening in the outer position that is larger than the cross sectionaldimension of the largest bale to be sheathed; said tubular bag beinggathered lengthwise to fit the length of the elongated support rods andin the gathered condition fitted to the support rods with the supportrods at the inner position, and said gathered tubular bag stretched bythe movement of the support rods to their outer position; and saidtubular bag provided with a closed rearward end and said bales uponbeing inserted into the bags and through the openings defined by thesupport rods being deposited at a stationary position in a sheathedcondition on the ground rearward of the machine, said machine beingmoved forward incrementally as determined by the bale bagging procedureto provide contiguous and stationary placement of the sheathed balesonto the ground.
 6. A system as defined in claim 5 including a balereceiving and bale guiding portion on said machine for guiding saidbales into and through the frame.
 7. A system as defined in claim 6wherein said portion is configured for engaging and receiving bales asthe machine is moved forward.
 8. A system as defined in claim 7including a tractor, said tractor coupled to said machine for pullingsaid machine along the ground to engage and guide bales from the groundinto and through the frame.